Efficient Computation of Null-Geodesic with Applications to Coherent Vortex Detection

Abstract

Recent results suggest that boundaries of coherent fluid vortices (elliptic coherent structures) can be identified as closed null-geodesics of appropriate Lorentzian metrics defined on the flow domain. Here we derive an automated method for computing such null-geodesics based on the geometry of the underlying geodesic flow. Our approach simplifies and improves existing procedures for computing variationally defined Eulerian and Lagrangian vortex boundaries. As an illustration, we compute objective vortex boundaries from satellite-inferred ocean velocity data. A MATLAB implementation of our method is available as supplementary material.

References in corpus (5)

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Cited by in corpus (8)

• A Critical Comparison of Lagrangian Methods for Coherent Structure Detection
• Transport by Lagrangian Vortices in the Eastern Pacific
• Finite-time Lyapunov exponents in the instantaneous limit and material transport
• Uncovering the Edge of the Polar Vortex
• Barriers to the Transport of Diffusive Scalars in Compressible Flows
• Vortex boundaries as barriers to diffusive vorticity transport in two-dimensional flows
• Emergent scar lines in chaotic advection of passive directors
• Hyperbolic Covariant Coherent Structures in two dimensional flows